LogFAQs > #961333456

That's the remaining life of the oil. Depending on the car it'll just measure mileage, while more sophisticated systems will compare miles to engine hours, throttle, outside temp, etc.

For my Challenger I'm on a strict 5k mile or 6 month schedule for my synthetic oil. Far as leaks go the cardboard idea is good, but doesn't beat a good old fashioned peek under the skirt to see what and where it's costing you money.